#include <bits/stdc++.h>
#include <ext/hash_map>
#include <ext/numeric>

using namespace std;
using namespace __gnu_cxx;

#define REP(i, n) for ((i) = 0; (i) < (n); (i)++)
#define rep(i, x, n) for ((i) = (x); (i) < (n); (i)++)
#define REV(i, n) for ((i) = (n); (i) >= 0; (i)--)
#define FORIT(it, x) for ((it) = (x).begin(); (it) != (x).end(); (it)++)
#define foreach(it, c)                                                         \
  for (__typeof((c).begin()) it = (c).begin(); it != (c).end(); ++it)
#define rforeach(it, c)                                                        \
  for (__typeof((c).rbegin()) it = (c).rbegin(); it != (c).rend(); ++it)
#define foreach2d(i, j, v)                                                     \
  foreach (i, v)                                                               \
    foreach (j, *i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define SZ(x) ((int)(x).size())
#define MMS(x, n) memset(x, n, sizeof(x))
#define mms(x, n, s) memset(x, n, sizeof(x) * s)
#define pb push_back
#define mp make_pair
#define NX next_permutation
#define UN(x) sort(all(x)), x.erase(unique(all(x)), x.end())
#define CV(x, n) count(all(x), (n))
#define FIND(x, n) find(all(x), (n)) - (x).begin()
#define ACC(x) accumulate(all(x), 0)
#define PPC(x) __builtin_popcount(x)
#define LZ(x) __builtin_clz(x)
#define TZ(x) __builtin_ctz(x)
#define mxe(x) *max_element(all(x))
#define mne(x) *min_element(all(x))
#define low(x, i) lower_bound(all(x), i)
#define upp(x, i) upper_bound(all(x), i)
#define NXPOW2(x) (1ll << ((int)log2(x) + 1))
#define PR(x) cout << #x << " = " << (x) << endl;

typedef unsigned long long ull;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef pair<int, int> pii;

const int OO = (int)2e9;
const double eps = 1e-9;

const int N = 30;

int n, m;
char a[N][N];

void solve() {
  //  each char will take the whole row
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (a[i][j] != '?') {
        for (int k = j - 1; k >= 0; k--) {
          if (a[i][k] == '?') {
            a[i][k] = a[i][j];
          } else {
            break;
          }
        }
        for (int k = j + 1; k < m; k++) {
          if (a[i][k] == '?') {
            a[i][k] = a[i][j];
          } else {
            break;
          }
        }
      }
    }
  }
  for (int i = 0; i < n; i++) {
    if (a[i][0] == '?') {
      for (int k = i - 1; k >= 0; k--) {
        if (a[k][0] != '?') {
          for (int j = 0; j < m; j++) {
            a[i][j] = a[k][j];
          }
          break;
        }
      }
      if (a[i][0] == '?') {
        for (int k = i + 1; k < n; k++) {
          if (a[k][0] != '?') {
            for (int j = 0; j < m; j++) {
              a[i][j] = a[k][j];
            }
            break;
          }
        }
      }
    }
  }
}

int main() {
  std::ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  //#ifndef ONLINE_JUDGE
  freopen("A-small-attempt1.in", "rt", stdin);
  freopen("out.txt", "wt", stdout);
  //#endif
  int t, tt = 1;
  cin >> t;
  while (t--) {
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
    }
    solve();
    cout << "Case #" << tt++ << ":"
         << "\n";
    for (int i = 0; i < n; i++) {
      cout << a[i] << "\n";
    }
  }
  return 0;
}
